When a patient with congestive heart failure (CHF) or end-stage liver disease (ESLD) doesn’t respond as expected to diuretic therapy, measurement of urinary sodium (Na) can be helpful.

In low effective arterial blood volume states (eg, CHF and ESLD) aldosterone secretion is high, resulting in high urine potassium (K) and low urine Na concentrations. However, in the presence of diuretics, urinary Na excretion should rise.

Patients undergoing active diuresis are often restricted to a 2 g (88 mEq) Na intake/day, with ~10 mEq excreted via non-urinary sources (primarily stool), and ~ 78 mEq excreted in the urine to “break even” — that is, to maintain the same weight.

Although historically measured 1, a 24-hour urine Na and K collection is tedious, making spot urine Na/K ratio more attractive as a potential proxy. Approximately 90% of patients who achieve a urinary Na/K ratio ≥1 will have a urinary Na excretion ≥78 mEq/day — that is to say, they are sensitive to the diuretic and will have a stable or decreasing weight at the current dose. 2,3

The “ideal” Na/K ratio as relates to responsiveness to diuretics has ranged from 1.0 to 2.5.4 In acutely decompensated heart failure patients on spironolactone, a K-sparing diuretic, Na/K ratio >2 at day 3 of hospitalization may be associated with improved outcome at 180 days. 5

Remember also that if the patient’s clinical syndrome is not correlating well with the ratio, it’s always a good idea to proceed to a 24-hour urine collection.

Less well-known is that congenital haptoglobin deficiency (“anhaptoglobinemia”) may not be so rare in the general population at a prevalence of 1% among whites and 4% among African-Americans (>30% in blacks of West African origin)3. Measurement of serum hemopexin, another plasma protein that binds heme, may help distinguish between this condition and acquired hypohaptoglobinemia— in the absence of hemolysis, hemopexin levels should remain unchanged3,5.

Final Fun Fact: Did you know that serum haptoglobin is often low during the first 6 months of life?

Cirrhotic patients with upper gastrointestinal bleed (UGIB) are at high risk of bacterial infections: 22% during the first 48 h after admission, 35-66% within 2 weeks of initial bleeding1. Antibiotic prophylaxis has been shown to reduce short term mortality, bacterial infections, early rebleeding and volume of blood transfused1-4.

But what is the exact connection between UGIB and bacterial infections in cirrhosis? One hypothesis is that UGIB sets up the host for bacterial infection via translocation (eg, due to hypovolemia), procedures necessary in the management of bleeding (eg endoscopy, sclerotherapy, IV access), and aspiration pneumonia. More intriguing is the reverse hypothesis—that is the bacterial infection serves as a trigger for UGIB. Several lines of evidence supportthis view1,2.

Cirrhotic patients admitted for non-UGIB-related conditions may be 4x more likely to develop UGIB during their hospitalization in the presence of bacterial infection on admission4

Bacterial infections are a common cause of morbidity and mortality in patients with cirrhosis, affecting about 30% of such patients either at admission or during their hospitalization, with an attendant risk of mortality that is twice that of individuals without cirrhosis1.

Two major mechanisms may account for the observed immune dysfunction in cirrhosis: 1. Compromise of the immune surveillance function of the liver itself through damage of the reticulo-endothelial system (RES) and reduced synthesis of innate immunity proteins and pattern recognition receptors (PRRs); and 2. Dysfunctions of circulating and intestinal population of immune cells2.

Damage to the RES in cirrhosis leads to portal-system shunting, loss/damage of Kupffer cells (specialized hepatic macrophages) and sinusoidal capillarization, all hindering blood-borne pathogen clearance. Cirrhosis is also associated with a defect in hepatic protein synthesis, including complement components, decreased PRRs and acute phase reactants (eg C-reactive protein), which may in turn lead to the impairment of the innate immunity and bacterial opsonization.

Cirrhosis can also cause reduction in the number and function of neutrophils (eg, decreased phagocytosis and chemotaxis), B, T, and NK lymphocytes, and decreased in bacterial phagocytosis by monocytes. In addition, damage to the gut-associated lymphoid tissue (eg Peyer’s patches and mesenteric lymph nodes) may facilitate bacterial translocation.

CRP is primarily synthesized by the liver mainly as a response to IL-6 production in inflammatory states1. Lower CRP production may then be expected in cirrhotic patients with significant infections and several studies support this view2.

In a particularly convincing study involving E. coli-infected patients with bacteremia, the median CRP level in cirrhotic patients was about 40% that of non-cirrhotic patients (62 mg/L vs 146 mg/L)3. In another study involving bacteremic patients with or without liver dysfunction, median CRP level was about 60% that of patients with preserved liver function (81 mg/L vs 139 mg/L)4. Some investigators have reported a cut-off CRP value of 9.2 mg/L as a possible screening test for bacterial infections in patients with cirrhosis with a sensitivity and specificity of 88% (AUROC 0.93)5.

Collectively, these data suggest that although CRP response may be diminished in patients with advanced liver disease and acute infection, its synthesis is still maintained.

Hepatocellular carcinoma (HCC) is the 3rd most common cause of cancer-related deaths1. Liver transplant removes the HCC tumor and addresses the underlying cirrhosis. Unfortunately, the demand for liver transplants exceeds the supply of available livers, making it necessary to select patients with the best recurrent-free survival following transplantation. .

Mazzaferro2 found that patients who had one lesion <5 cm, no more than 3 lesions each ❤ cm, and no extrahepatic involvement or vascular invasion had significantly higher rates of recurrent-free survival following liver transplant than patients with tumors exceeding this criteria (92% vs 59% at 4 years, respectively, P = .002). This criteria, also known as the Milan criteria, has been substantiated by numerous studies3 and widely adopted. Other more inclusive criteria has also been proposed, including the UCSF criteria4 (one tumor <6.5 cm, no more than 3 tumors, all <4.5 cm and cumulative size <8cm) which have good survival rates, but have not been adopted due to limited supply of available livers.

Interestingly, patients with HCC not initially meeting the Milan criteria but who receive treatment to meet the criteria have similar post-transplantation recurrence-free survival rates as those who meet the criteria without downstaging4,5.

Yes! Besides expanding the circulatory plasma volume by raising the oncotic pressure, albumin appears to have a vasoconstricting effects by binding to endotoxins, nitric oxide (NO), bilirubin and fatty acids1,2.

Splanchnic vasodilatation, a feature of decompensated cirrhosis (eg ascites, bleeding varices, hepatorenal syndrome, and hepatic encephalopathy), is accentuated by superimposed infections through cytokine-mediated release of endothelial vasodilators3. By binding to potential vasodilators such as bile acids, endotoxins and NO, albumin may also help restore endothelial function and act as a vasoconstrictor.

In a cool study involving patients with SBP randomized to either albumin or hydroxyethyl starch (HS, a synthetic volume expander), the albumin (not HS) group had a significant increase in mean arterial pressure, right atrial pressure, pulmonary artery pressure, systolic volume, left ventricular stroke work, and systemic vascular resistance3.

Albumin may also have an immune-modulating activity in patients with cirrhosis or acute liver decompensation by binding to prostaglandin E-2 (PGE-2), generated as a result of inflammatory reaction in the liver and bacterial translocation4. PGE-2 is a suppressor of macrophage cytokine secretion and bacterial killing. By binding to PGE-2, albumin can reverse this immunosuppression by reducing the availability of serum PGE-2.